441
FXUS65 KTFX 242326
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
426 PM MST Mon Nov 24 2025

Aviation Section Updated.

.KEY MESSAGES...

 - Scattered snow showers will continue this afternoon and evening
   along and north of I-90.

 - Gusty winds continue across the region today.

 - Tuesday and Wednesday remains calmer, with light mountain snow
   on Wednesday.

 - Colder and slightly snowier for post-Thanksgiving travel.

&&

.DISCUSSION...
/Issued 254 PM MST Mon Nov 24 2025/

 - Meteorological Overview:

The current shortwave trough is passing through, and will
continue to bring scattered to widespread snow showers for areas
mainly along and north of I-90 through the afternoon. This will
transition to more widespread stratiform light snow this evening
through late tonight. Although snowfall accumulations will remain
light across lower elevations, these snow showers will cause
rapid reductions in visibility. Stronger mid level winds will
keep gusty winds across the region through mostly sunset today.
Central MT will see these stronger winds linger until late
tonight. This low pressure system will push off to the southeast
during the overnight hours, drying out the region. Overnight,
there will be some slight clearing in the clouds. Given recent
snowfall, there is a slight chance for some patchy fog/low stratus
Tuesday morning. Any pavements that are still wet overnight
tonight, will freeze with overnight temperatures dropping into the
20s to teens.

After this system passes, northwest flow aloft settles in behind.
Tuesday looks on track to remain dry with temperatures remaining
near normal. Wednesday, a weak shortwave moves through the region,
bringing another round of precipitation. However, weak forcing
and small amounts of moisture will keep snowfall light over the
mountains with a rain/snow mix across lower elevations.

Heading into the Thanksgiving Holiday time period, a front
lifting north looks to bring some widespread light snow
throughout the day. Models begin to diverge a bit Thanksgiving
onwards. There is still some variations in the timing of
precipitation and amounts Thanksgiving through the weekend.
Ensembles still hint at colder temperatures also moving in this
weekend. There remains uncertainty on how cold it gets based on
this model variation in the evolution of the trough forming along
the West Coast U.S. Main messaging is, expect colder and slightly
snowier conditions this weekend. Expect at least minor winter
impacts to post holiday travel, especially over mountain passes.


 - Forecast Confidence & Scenarios:

Additional Snowfall Today:

Additional snowfall amounts will remain light across lower
elevations and more minor along the remaining mountain passes.
However, this afternoon King`s Hill/Bears Paw and the Eastern
Glacier Park zone could see some moderate banding in snow.
Conditions still look to stay below Winter Storm Warning Criteria
through the evening, but we will continue to monitor for any
heavier snow banding that develops.

Along the Hi-line towards the Canadian border, a more minor
additional accumulations of up to 3" can be expected, so the
Winter Weather Advisory remains in effect until late tonight.

Winds Today:

Probabilities for peak winds haven`t changed too much, and the
current wind forecast seems be be on track this afternoon. The
main area to watch for this evening is southeastern Fergus County.
Hi-res guidance shows and isolated chance for some high winds
down there, but since it`s in a localized area I am not confident
to issue a High Wind Warning down there.


Snow Later This Week:

With variations of the timing and position of the next coming
shortwave on Thanksgiving/Friday, it`s hard to pin point some
details out including snowfall amounts. However, ensembles give a
20-50% chance for two inches of snow across the lower elevations
Thursday/Friday. The Northern Rockies/Eastern Glacier Park region
have the potential to see more minor to moderate snowfall, with
Marias Pass having a 50% chance for 6" of snow. -Wilson


&&

.AVIATION...
25/00Z TAF Period

Main concern is scattered snow showers moving southward through
the CWA this evening. Visibility could fall below one mile for a
short time. Most snow showers should diminish by 09z. There is
some potential for fog towards 12z where clearing occurs, but the
probability is too low at this time to include in the TAF.
Mountains/passes will be obscured across the CWA through at least
09z Tue. Brusda

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  21  38  25  41 /  60   0  10  20
CTB  13  34  15  36 /  30   0  10  10
HLN  18  35  24  41 /  50   0  30  30
BZN  15  34  21  41 /  20   0  30  30
WYS   5  29  15  33 /  10   0  50  60
DLN  14  35  22  43 /   0   0  10  10
HVR  16  34  12  31 /  90   0   0  10
LWT  15  35  19  38 /  70   0   0  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 11 PM MST this evening for Bears
Paw Mountains and Southern Blaine-Big Belt, Bridger and Castle
Mountains-East Glacier Park Region-Hill County-Little Belt and
Highwood Mountains-Northern Blaine County-Southern Rocky
Mountain Front.

&&

$$
http://www.weather.gov/greatfalls